package com.cenntro.common.util;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Random;

import org.apache.commons.codec.binary.Hex;
import org.apache.commons.lang3.StringUtils;

import com.google.common.base.Joiner;

public class MessageDigestUtil {

//	 public static String MD51(String s) {
//	 try {
//	 MessageDigest md = MessageDigest.getInstance("MD5");
//	 byte[] bytes = md.digest(s.getBytes("utf-8"));
//	 return toHex(bytes);
//	 } catch (Exception e) {
//	 throw new RuntimeException(e);
//	 }
//	 }
//	
//	 private static String toHex(byte[] bytes) {
//	
//	 final char[] HEX_DIGITS = "0123456789abcdef".toCharArray();
//	 StringBuilder ret = new StringBuilder(bytes.length * 2);
//	 for (int i = 0; i < bytes.length; i++) {
//	 ret.append(HEX_DIGITS[(bytes[i] >> 4) & 0x0f]);
//	 ret.append(HEX_DIGITS[bytes[i] & 0x0f]);
//	 }
//	 return ret.toString();
//	 }
//	//


	/**
	 * 普通MD5
	 * 
	 * @author daniel
	 * @time 2016-6-11 下午8:00:28
	 * @param inStr
	 * @return
	 */
	public static String MD5(String input) {
		MessageDigest md5 = null;
		try {
			md5 = MessageDigest.getInstance("MD5");
		} catch (NoSuchAlgorithmException e) {
			return "check jdk";
		} catch (Exception e) {
			e.printStackTrace();
			return "";
		}
		char[] charArray = input.toCharArray();
		byte[] byteArray = new byte[charArray.length];

		for (int i = 0; i < charArray.length; i++)
			byteArray[i] = (byte) charArray[i];
		byte[] md5Bytes = md5.digest(byteArray);
		StringBuffer hexValue = new StringBuffer();
		for (int i = 0; i < md5Bytes.length; i++) {
			int val = ((int) md5Bytes[i]) & 0xff;
			if (val < 16)
				hexValue.append("0");
			hexValue.append(Integer.toHexString(val));
		}
		return hexValue.toString();
	}

	/**
	 * 加盐MD5
	 * 
	 * @author daniel
	 * @time 2016-6-11 下午8:45:04
	 * @param password
	 * @return
	 */
	public static String generate(String password) {
		Random r = new Random();
		StringBuilder sb = new StringBuilder(16);
		sb.append(r.nextInt(99999999)).append(r.nextInt(99999999));
		int len = sb.length();
		if (len < 16) {
			for (int i = 0; i < 16 - len; i++) {
				sb.append("0");
			}
		}
		String salt = sb.toString();
		password = md5Hex(password + salt);
		char[] cs = new char[48];
		for (int i = 0; i < 48; i += 3) {
			cs[i] = password.charAt(i / 3 * 2);
			char c = salt.charAt(i / 3);
			cs[i + 1] = c;
			cs[i + 2] = password.charAt(i / 3 * 2 + 1);
		}
		return new String(cs);
	}

	/**
	 * 校验加盐后是否和原文一致
	 * 
	 * @author daniel
	 * @time 2016-6-11 下午8:45:39
	 * @param password
	 * @param md5
	 * @return
	 */
	public static boolean verify(String password, String md5) {
		char[] cs1 = new char[32];
		char[] cs2 = new char[16];
		for (int i = 0; i < 48; i += 3) {
			cs1[i / 3 * 2] = md5.charAt(i);
			cs1[i / 3 * 2 + 1] = md5.charAt(i + 2);
			cs2[i / 3] = md5.charAt(i + 1);
		}
		String salt = new String(cs2);
		return md5Hex(password + salt).equals(new String(cs1));
	}

	/**
	 * 获取十六进制字符串形式的MD5摘要
	 */
	private static String md5Hex(String src) {
		try {
			MessageDigest md5 = MessageDigest.getInstance("MD5");
			byte[] bs = md5.digest(src.getBytes());
			return new String(new Hex().encode(bs));
		} catch (Exception e) {
			return null;
		}
	}

	 // 测试主函数  
    public static void main(String args[]) {  
    	String[] a = {" "};
    	System.out.println("$$$$"+ MessageDigestUtil.generate(""));
    	System.out.println("##" + StringUtils.join(a) + "##");
        // 原文  
        String plaintext = "DingSai";  
    //  plaintext = "123456";  
        System.out.println("原始：" + plaintext);  
        System.out.println("普通MD5后：" + MessageDigestUtil.MD5(plaintext));  
  
        // 获取加盐后的MD5值  
        String ciphertext = MessageDigestUtil.generate(plaintext);  
        System.out.println("加盐后MD5：" + ciphertext);  
        System.out.println("是否是同一字符串:" + MessageDigestUtil.verify(plaintext, ciphertext));  
        /**  
         * 其中某次DingSai字符串的MD5值  
         */  
        String[] tempSalt = { "c4d980d6905a646d27c0c437b1f046d4207aa2396df6af86", "66db82d9da2e35c95416471a147d12e46925d38e1185c043", "61a718e4c15d914504a41d95230087a51816632183732b5a" };  
  
        for (String temp : tempSalt) {  
            System.out.println("是否是同一字符串:" + MessageDigestUtil.verify(plaintext, temp));  
        }  
    }  
    
    
}
